Thomson scattering X-ray sources have many features which are of relevance for several applications: the main one is the capability to produce intense, quasi-monochromatic, tunable X-ray beams, after collimation, still with a reasonably small size apparatus. Applications to medical physics are straightforward, in particular in mammography where dose control in screening programs is the main relevant issue. An optimal choice of the X-ray energy to image the breast will result in a best image quality and hence will lead to a dose reduction. A Thomson scattering source is presently under development at the Frascati National Laboratories (LNF) of INFN (Istituto Nazionale di Fisica Nucleare). A complete simulation of the source including electron beam, laser beam, Thomson interaction and X-ray imaging is presented. The X-rays are generated in the energy range suitable for mammography and used to generate images of a mammographic phantom. Image quality is evaluated in terms of dose efficiency and compared to those obtained by monochromatic beams and conventional X-ray tubes. (C) 2010 Elsevier B.V. All rights reserved. RI Oliva, Piernicola/E-5839-2012